Geometric compasses.



E. F. WOLTIMUSEN.

l GEOMETRIC COMPASSES. lAPPI.,IC!\`I'ICIN FILED AUG31V| i917.

LZSSASQ., A Patented Apr. 16, 19m

Edwin F.]21lihause11 arriere. f`

EDWIN r. WoLrHAUsEN, or DULUTH, ivrrNNaso'rA.

GEOMETRIC COMPASSES.

TQQZZ whom it may concern:

Be it known that I, EDWIN F. WoLTHAUsEN, fa citizen -of the United States, residing at Duluth, in the county of St. Louis and State vof Minnesota, have invented new and useful in2i} no.'ements in Geometric Compasses, of

which the following' is a specification.

This invention is a compass attachment wherein the stationary point of the compass may be properlyl positioned and securely held against movement when drawing large circles or arcs. i

One object of the invention is to provide an attachment for Compasses wherein the stationary point may be accurately located and visible at all times and yet be retained in its original position.

Another object of the invention is to provide an attachment having a vacuum cup that is adapted to be attached to one of the legs of a compass and by means of anl arm the vacuum cup is spaced from the point carried by the leg of the compass.

Broadly stated the invention comprises a vacuum cup having means to cause the cup to engage with a. surface and an arm extend-v ing from the cup which arm is provided with means for engaging with the point of a cornpass.

One practical form of construction and assembly will be described and illustrated in the accompanying drawings, in which- Figure 1 is a side elevation of a compass and the attachment.

Fig. 2 is a vertical sectional view of the vacuum cup and arm and v Fig. 3 is a top plan view of the vacuum cup and arm.

In the preferred embodiment about to be described, a black-board compass is shown having the lees 5 and 6. The legs may be pivotally connected together as indicated by the joint 7. The joint 7 may also include the handle 8. The joint 7 should preferably be made so that the legs may be frictionally held at any desired point of separation. As shown, the leg 5 has attached thereto a holder generally indicated at 9. This holder 9 may be formed of any suitable material and is preferably so constructed to hold a piece of chalk 10 therein. If desired the holder may be of the split or clamping type, the sections of which are held together by means of the clamping screw 11. The holder 9 thus provides for the adjusting piece of chalk 10.

Specification of Letters Patent.

Yas shown. .section l5., an '-erably extends at 'rig-ht vangles thereto.

ratentedapr. ie, reis.

Application fired august 31, 1917. serial No. 189,212.

The leg 6 may be provided with the usual stationary point, one form of which is indi' cated at 12. `This point is preferably so constructed that it will engage with the center point of the arc or circle which iiser desiresconstructed. rlhe point -12 may be proi vided with a iedu ed v"cylinii"rical section 13 o cooperate with this reduced Varm 14 lis employed that pref- To position it may hold this arm 14 in its proper be secured, to the point 12 and 1n proper position relative to the reduced section 13 by means of clamping screws 15. These screws may serve to hold a detachable section if so desired.Y p

Any form of attachment may be utilized which will permit I with respect to the point 12 and the reduced section 13. The other end of the arm 14 is provided with a suction cup 16 which may be of any usual type of construction. In the present instance the cup is provided with a depressed surface 17 upon its under side. l

In order to hold the' cup 16 in its proper `position upon the arm 14, the 'cup is provided with vsuitable engaging' means, one form of which is indicated at 18. One end of this engaging means extends beyond the sul face'of the cup and is preferably threaded at 19 as shown. vThe threaded portion 19 is adapted to engage with a suitable holderhaving threads formed therein which is car'- ried by the arm 14.

As shown, the vacuum cup is attached to the under side of the arm 14. Mounted upon the upper side of the armV 14 is a knob 20l which as shown is provided with an upper Hat face 21. 1t is preferred to make the vacuum cup 16 of circular form, and also to form the knob 20 in a similar manner.

The cup 16 is preferably formed of-rubber so that it may readily adhere to more or less uneven surfaces. formed of any suitable material, and is employed for the purpose of pressing the cup into engagement with a surface to expel the air from beneath the vacuum cup 16. When thisattachment is secured to a compass large 105 arcs and circles may be drawn and the stationary point 12 will be maintained at its proper place.. The point 12 may be located at the point of erection ofthe circle or arc,

and as the vacuum cup is spaced from the 110 point 12 the point is always visible.`

the arm `14 to rotate freely 'I The knob 2O may be 100 The leg 6 1s adapted to rotate in the arm comprises la by means of the reduced section or portion 13, so that in the present illust-ration the leg` carrying the chalk l() will rotate entirely around the attachment. Y

The leg 6 and the point 12 may loe con nected together hy means of a joint 22 that will provide for more or less universal movement. Any type of joint may be used for this purpose. l f

llVhat is claimed is l. An attachment tor compasses*employed tor drawing large geometrical figuresi which a vacuum cup adapted to he secured to a surface through atmospheric pressure, an arm extending from said cup, means `for seemingthe arm to a leg ot a compass to permit same to rotate with respect to the arm7 the spacing,- of said cup from the leg to which it is attached providing or the Visibility of the striking point of the ligure during construction. 1

2. rEhe combination with a compass, of a vacuum cup, a laterally extending arm secured to said cup a pointed element swiveled in said arm and means for pivotally securing the pointed element to one leg` of the compass.

The combination with a compass7 of an arm having one end secured to one leg` of the compass in a manner to permit of the rotation of said leg', a vacuum cup provided with a threaded 'extension engagea-ble with the opposite end ot said arm, a securing element threadedly engaging said extension tohold the arm inposition and having a' relatively broad upper sur-tace. f

n testimony Whereoflattix my signature.

EDVIN F. TNOLTHAUSEN.

Copies o'this patent may be obtained for five cents each, by addressing the Ccmmissicner et @atenta Washingtcn, D. G. Y 

